Setup Constraints for modular conveyor
You could use a method similar to the one shown here, mounting the plates on a moving array of supports on the curve, to avoid deformation.

But since you would want some variety in the plates, you could use a Particle System  emitted by the support-array, with settings as illustrated, rather than face-instancing:



EDIT: Thanks, @MrQuery, for pointing out a possible source of error with the rig as described. It turns out, to make it more robust, you should specify the rotation of the particles, as well as the settings above:



The phase, rotation, may vary with your plate model: orientation of its mesh with respect to its axes, (which can also be adjusted in Edit Mode).

The emission is all at frame 1 of long-lived particles, one per face, with no physics or randomness. 'Count' is used to give an ordered, cyclic, selection from the source Collection of particle variants.